<html>
<script>
var person = {
name:"dwqs",
age:20,
interesting:"coding",
blog: "www.ido321.com"
};
//定义sex属性，writable是false,所以不能修改
Object.defineProperty(person,"sex",{
writable:false,
value:"male"
});
console.log(person.sex); //male

//在严格模式下出错，非严格模式赋值被忽略
person.sex = "Jerry";
console.log(person.sex); 
var prop = Object.getOwnPropertyDescriptor(person,"sex");
debugger;
</script>
</html>